Reversing valve

Abstract

A reversing valve for use in air conditioning systems and the like for controlling the flow of fluid between a plurality of ports, the valve including a valve body with a chamber communicating with each of the ports, and a valve member mounted in the chamber for movement between two positions to control the flow. Means for moving the valve member are located to one side and generally centrally of the valve member, and include a reciprocable operating plunger engaging a grooved ramp in the valve member which forms a cam. A spring is provided at one end of the valve member to urge the valve member to one position as the plunger is retracted.

We claim: 
     
       1. A valve for controlling the flow of fluid between plural ports, said valve comprising: (a) a valve body with a chamber communicating with each of said ports;   (b) a valve member movably mounted in said chamber for sliding movement between at least two positions to control said flow;   (c) means for yieldably urging said valve member to one of said positions;   (d) means for moving said valve member to the other of said positions against said urging means comprising an actuater disposed to one side of and generally centrally of said valve member and including a reciprocable plunger movable transversely to the path of said valve member; and   (e) a cam surface on said valve member engaged by said plunger, said cam surface comprising a ramp extending longitudinally of said valve member and engaged by said plunger for movement of said plunger on said ramp, the uppermost portion of said ramp being sloped more steeply than the remainder thereof to provide initially greater motive forces as said plunger moves along said ramp.   
     
     
       2. A valve for controlling the flow of fluid between plural ports for use in air conditioning systems and the like, said valve comprising: (a) a valve body with a chamber communicating with each of said ports;   (b) a valve member mounted in said chamber for movement between two positions to control said flow;   (c) means for moving said valve member between said positions comprising an electrically activated wax element disposed to one side and generally centrally of said valve member, an extendable and retractable plunger operable by the wax element, to travel transversely to the path of said valve member, and a grooved ramp in said valve member extending longitudinally of the valve member to receive said plunger; and,   (d) spring means opposing movement of said valve member caused by the extension of said plunger.   
     
     
       3. A flow control valve having a body with a chamber and a plurality of ports communicating with said chamber, a valve member having a relatively flat surface engaging a flat face of the valve body and having a flow passage at said flat surface, said valve member being movable between two positions to vary the connection of said flow passage to said ports, means urging said valve member to one of said positions, an inclined cam surface on said valve member at a side thereof opposite said flat surface, a reciprocable plunger operatively engageable with said cam surface, and means for exerting a force on the plunger having a magnitude sufficient to act on the cam surface and maintain said valve member and body surfaces in contact and a selectively greater force to extend the plunger to act on said cam surface and impart a component of force on said valve member in a direction to move the valve member against said urging means. 
     
     
       4. A valve as defined in claim 3 wherein said force exerting means comprises an electrically heated wax expansion element. 
     
     
       5. A valve as defined in claim 4 wherein said cam surface has its upper section operatively engaged by the plunger when retracted and said upper section has a steeper slope than the remainder thereof to provide a greater component of force to initially move the valve member. 
     
     
       6. A valve as defined in claim 4 wherein one of said ports opens to a first end of said chamber and at a side of the valve opposite a valve side having a port opening to a second end of said chamber, said urging means including a spring in said first end of the chamber, said valve member having a section closely fitted to said valve body to prevent leakage therepast, and the surface of the valve opposite said flat surface being relieved adjacent said valve member section to place said last mentioned ports in communication as the valve member moves against said spring. 
     
     
       7. A valve as defined in claim 4 wherein said valve member is of molded plastic. 
     
     
       8. A flow control valve for controlling the flow of fluid between plural ports for use in air conditioning systems and the like, comprising, a valve body with a chamber having a flat surface and a plurality of ports communicating with said chamber and said flat surface including a pair of ports leading to a separate pair of coils and an intermediate port connectable to compressor suction, a valve member in said chamber and having a relatively flat surface engaging said flat surface of the valve body, an arcuate flow passage in said valve body whereby positioning of the valve member in either of two positions causes said flow passage to connect one or the other of the coil ports to said intermediate port, a spring in one end of said chamber urging said valve member to one of said two positions, an inclined cam surface on said valve member at a side thereof opposite said relatively flat surface and inclined downwardly toward an end of the chamber opposite the end having said spring and having an initial section at a steeper slope, a reciprocable plunger movably guided by said valve body for movement in a direction normal to the movement of the valve body and having a roller engaging said inclined cam, an electrically-activated wax element associated with said plunger for causing movement of the plunger whereby extension of the plunger moves the valve member against the action of the spring, a surface at the end of the inclined cam engaged by said roller after movement of the valve body whereby a force exerted by the plunger maintains said flat surfaces in sealing engagement, an additional port opening to said chamber at a side of the valve body opposite said flat surface an opening to the end of the chamber having the spring, said valve member having a section closely fitted to said valve body to prevent leakage therepast, and the surface of the valve member opposite said flat surface being relieved adjacent said valve member section to place said additional port in communication with a different one of said coil ports as the valve member is moved against the action of said spring. 
     
     
       9. A valve for controlling the flow of fluid between plural ports, said valve comprising: (a) a valve body with a chamber communicating with each of said ports;   (b) a valve member movably mounted in said chamber for sliding movement between at least two positions to control said flow;   (c) means for yieldably urging said valve member to one of said positions;   (d) means for moving said valve member to the other of said positions against said urging means comprising an actuater disposed to one side of and generally centrally of said valve member and including a reciprocable plunger movable transversely to the path of said valve member; and   (e) a cam surface on said valve member engaged by said plunger, said cam surface comprising a ramp extending longitudinally of said valve member and engaged by said plunger for movement of said plunger on said ramp, said plunger including a roller on its lower end for engagement with and movement on said ramp.   
     
     
       10. A flow control valve having a body with a chamber having a face and a plurality of ports at said face communicating with said chamber, a valve member having a surface engaging said face of the valve body and having a flow passage at said surface movable between two positions to vary the connection of said flow passage to said ports, means urging said valve member to one of said positions, a cam surface on said valve member at a side thereof opposite said surface, a reciprocable plunger operatively engageable with said cam surface, and means for exerting a force on the plunger having a magnitude sufficient to act on the cam surface and maintain said valve member and body in contact and a selectively greater force to extend the plunger to act on said cam surface and impart a component of force on said valve member in a direction to move the valve member against said urging means.